I don't think anyone is faulting Tailscale for using their blog to advertise, and no one is faulting Tailscale for how they handled this situation in general, or their response to it.

The issue is acting like their response is 'brave' in anyway, or altruistic. It can be considered admirable only to the extent any company doing a good job running its business can be.

This is a good, smart response to what happened. They are approaching this incident as a way to improve their product and offer a better service to their customers. That is good, and it is fine to reward them with your business in response. There is nothing wrong with making good business decisions, but it isn't something that we need to unduly respect.